An Investigation of Consolidants Penetration in Wood. Part 2: FTIR Spectroscopy

FTIR spectroscopy was used in this work for studying the penetration of some consolidants frequentlyused in old wood conservation into test pieces of sound spruce wood (Picea abies) wood. Thin microsections(30-60 μm) of control and treated wood were analysed in reflectance mode using an ATR system. Theconsolidation products investigated were Paraloid B72, bee wax, a mixture of bee wax / linseed oil and twotypes of paraffins. These products presented FTIR spectra with characteristic common and specific bands,allowing their identification in the treated wood with no impediments coming from their colour, transparencyor the percent of cell lumena filling. The treatment of wood with these products brought about alterations ofthe spectra aspect by the appearance or intensification of some characteristic bands and the modification ofthe ratio between the areas of some characteristic absorption bands so that a qualitative and semiquantitativeevaluation of the presence and penetration depth and distribution of these consolidationproducts in wood was possible, proving the adopted method as valuable and useful for further research inthis field

Wood Species Identification, A Challenge of Scientific Conservation

Wood species identification is an important step in the scientific approach of conservation of the wooden cultural heritage. The paper refers to the microscopic identification of the wooden species for two artisanal objects, investigated for conservation purposes. A previous macroscopic analysis of these objects, after thorough cleaning of the surfaces offered some basic information on the possible wood species involved, but due to the degradation of the support this was not conclusive for some elements of these objects, so that relevant samples were taken out, prepared and investigated. The identified wooden species were: poplar (Populus spp), sycamore (Acer pseudoplatanus), fir and beech (Fagus sylvatica). This identification was based on the microscopic keys of wood identification, reference microscopic slides of the respective wood species and microscopic measurements followed by data processing employing the ImageJ software

Comparative Assessment of Antifungal Potential of Clove (Eugenia caryophyllata) and Cinnamon (Cinnamomum verum) Essential Oils

The paper refers to the comparative evaluation of the potential antifungal effect of two essential oils: clove (Eugenia caryophyllata) essential oil and cinnamon (Cinnamomum verum) essential oil, against a brown rot fungus (Postia placenta) and a white rot fungus (Trametes versicolor). The screening test employed in this research demonstrated the biocidal antifungal potential of the two essential oils against both fungi tested. Cinnamon essential S-EO showed biocidal effect against white rot Trametes versicolor from 1% concentration and against brown rot Postia placenta from 10% concentration. Clove essential oil CEO showed biocidal effect against both types of fungi, brown and white rot, from 1% concentration. Both esssential oils tested were more active against the brown rot fungus Postia placenta than the white rot fungus Trametes versicolo

An Insight Into Beech Wood (Fagus Sylvatica L.) Degradation in Outdoors, Above Ground, Long-Time Exposure. Part 2: In-Time Evolution of Degradation, Destructive Evaluation After 7 Years and Influence of Exposure Situation

The paper is referring to some results of amodified L-Joint test, within which control andtreated beech wood samples were exposed andexamined periodically for 7 years. The long-termprotective effects of some surface treatments andthe in-time evolution of degradation in correlationwith the risk of wetting were examined, the paperbeing divided in two parts. The first part presentedthe complex degradation of wood and coatings, atmacroscopic and microscopic level after 7 years ofoutdoors, above ground exposure, employing a nondestructiveevaluation system.This second part of the paper deals with timesequences in beech wood degradation and in-timeevolution of the degradation phenomena as afunction of the exposure situation. Moreover,destructive evaluation of the samples after 7 years ofexposure offered a real insight into wooddegradation by revealing inner decay anddiscolouration as result of progress of thesedegradation types, from the tenon area or thesamples surface towards their interior.The surface treatments applied had only alimited protective effect on the evolution ofdegradation, while the differences between thedifferent investigated areas in correlation with therisk of wetting, induced a large variability in theexperimental data. However, this research revealedthe utility and versatility of the employed modified Ljointtest for a realistic evaluation of the potential of different treatments in improving beech performancein outdoor, above ground conditions

AN INSIGHT INTO BEECH WOOD (Fagus sylvatica L.) DEGRADATION IN OUTDOORS, ABOVE GROUND, LONGTIME EXPOSURE Part 1: Degradation and influence of surface treatments revealed by nondestructive evaluation after 7 years

Beech (Fagus sylvatica L.) is an important woodspecies in Romania and research looking at thepossibilities of improving beech wood properties,especially durability and dimensional stability for anextension and diversification of utilisation towardsoutdoors, above ground applications (UC3) is of greatinterest. In this respect, it is important to study andunderstand the complex degradation phenomenaoccurring in time under these conditions and to testthe efficiency of the protective treatments inappropriate field tests. The research presented in thispaper aimed to evaluate the degradation of controland treated beech wood samples after seven yearsexposure in a modified L-Joint test. A non-destructiveevaluation system was employed and the differentaspects of the complex degradation of wood andcoatings, at macroscopic and microscopic level arepresented. The influence of a preservation treatmentwith a reference biocide product and further coatingwith an alkyd white paint and a brown alkyd semitransparentlasure is also discussed. Discoloration bymould and staining fungi and cracks were the maindegradation phenomena occurring on the externalfaces and in the joint area (tenon). Decay was presenton some treated samples, but not in a large extent,being ranked up to maximum average values of 2 in the tenon area and 1.5 on the external surfaces ofsome samples.The simple surface treatments applied had only aslight effect of reducing wood degradation over such along period of time. The best results were obtained forthe samples treated with biocide before finishing withthe alkyd white paint.In all cases the variability of wood as a naturalmaterial corroborated with the reduced number ofreplicate test samples (3) and possible smalldifferences in the actual testing conditions (moisturecontent variations between samples) should beconsidered when analysing the experimental results

Atrasentan and renal events in patients with type 2 diabetes and chronic kidney disease (SONAR): a double-blind, randomised, placebo-controlled trial

Background: Short-term treatment for people with type 2 diabetes using a low dose of the selective endothelin A receptor antagonist atrasentan reduces albuminuria without causing significant sodium retention. We report the long-term effects of treatment with atrasentan on major renal outcomes. Methods: We did this double-blind, randomised, placebo-controlled trial at 689 sites in 41 countries. We enrolled adults aged 18–85 years with type 2 diabetes, estimated glomerular filtration rate (eGFR)25–75 mL/min per 1·73 m 2 of body surface area, and a urine albumin-to-creatinine ratio (UACR)of 300–5000 mg/g who had received maximum labelled or tolerated renin–angiotensin system inhibition for at least 4 weeks. Participants were given atrasentan 0·75 mg orally daily during an enrichment period before random group assignment. Those with a UACR decrease of at least 30% with no substantial fluid retention during the enrichment period (responders)were included in the double-blind treatment period. Responders were randomly assigned to receive either atrasentan 0·75 mg orally daily or placebo. All patients and investigators were masked to treatment assignment. The primary endpoint was a composite of doubling of serum creatinine (sustained for ≥30 days)or end-stage kidney disease (eGFR <15 mL/min per 1·73 m 2 sustained for ≥90 days, chronic dialysis for ≥90 days, kidney transplantation, or death from kidney failure)in the intention-to-treat population of all responders. Safety was assessed in all patients who received at least one dose of their assigned study treatment. The study is registered with ClinicalTrials.gov, number NCT01858532. Findings: Between May 17, 2013, and July 13, 2017, 11 087 patients were screened; 5117 entered the enrichment period, and 4711 completed the enrichment period. Of these, 2648 patients were responders and were randomly assigned to the atrasentan group (n=1325)or placebo group (n=1323). Median follow-up was 2·2 years (IQR 1·4–2·9). 79 (6·0%)of 1325 patients in the atrasentan group and 105 (7·9%)of 1323 in the placebo group had a primary composite renal endpoint event (hazard ratio [HR]0·65 [95% CI 0·49–0·88]; p=0·0047). Fluid retention and anaemia adverse events, which have been previously attributed to endothelin receptor antagonists, were more frequent in the atrasentan group than in the placebo group. Hospital admission for heart failure occurred in 47 (3·5%)of 1325 patients in the atrasentan group and 34 (2·6%)of 1323 patients in the placebo group (HR 1·33 [95% CI 0·85–2·07]; p=0·208). 58 (4·4%)patients in the atrasentan group and 52 (3·9%)in the placebo group died (HR 1·09 [95% CI 0·75–1·59]; p=0·65). Interpretation: Atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease who were selected to optimise efficacy and safety. These data support a potential role for selective endothelin receptor antagonists in protecting renal function in patients with type 2 diabetes at high risk of developing end-stage kidney disease. Funding: AbbVie

Modification of Shellac with Clove (Eugenia caryophyllata) and Thyme (Satureja hortensis) Essential Oils: Compatibility Issues and Effect on the UV Light Resistance of Wood Coated Surfaces

Shellac (SL) is a natural resin employed for wood finishing, while clove (Eugenia caryophyllata) and thyme (Satureja hortensis) essential oils (C-EO, T-EO) are organic natural products of vegetal origin with antifungal, antimicrobial and antioxidant properties. The present paper aims at exploring the potential of modifying alcoholic shellac solutions with essential oils (C-EO, T-EO), focussing on the recurrent effects of this modification on the traditional wood finishing technique, the colour and the UV light resistance of the wood coated surfaces. The compatibility of C-EO and T-EO with ethyl alcohol and the alcoholic reference SL solution was evaluated, and modified SL solutions with a content of 5% and 10% C-EO and T-EO were prepared. Wood samples of European maple (Acer pseudoplatanus) and European walnut (Juglans regia) were finished with reference and modified SL solutions. An accelerated UV ageing test was run, and the samples were evaluated after 24, 48 and 72 h of exposure. Colour measurements in the CIELab system and FTIR&ndash;ATR investigation were employed for monitoring colour and surface chemistry changes. Coating with SL resulted in visible colour changes for both wood species (&Delta;E values of 31.06 for maple and 13.00 for walnut) and increased UV resistance, reducing colour changes after 72 h UV exposure (by 83% for maple and by 59% for walnut) as compared to the uncoated controls. Modification of SL solutions with C-EO and T-EO only slightly influenced the colour of finished surfaces (&Delta;E = 1.88&ndash;5.41 for maple, &Delta;E = 1.36&ndash;3.41 for walnut) and their UV resistance. The colour changes (&Delta;E) of coated surfaces after 72 h exposure varied in the range 1.63&ndash;4.53 for maple and 2.39&ndash;3.58 for walnut, being generally slightly higher (by 1.7&ndash;2.9 units for maple and 0&ndash;1 unit for walnut) for the modified SL solutions. FTIR investigation highlighted only minor chemical changes of the shellac coating films after 72 h of UV exposure. A photo-induced oxidative process of eugenol seemed possible in the case of SL modified with C-EO

ASSESSING PROTECTING EFFICIENCY OF SOME SURFACE TREATMENTS ON FIR WOOD AFTER 7 YEARS OUTDOOR EXPOSURE

Performance of wood preservatives or coatings as surface treatments products is closely connected to different needs and requirements. This paper investigated the protective efficiency of such products, on fir wood exposed outdoors for 7 years, in a modified L-joint test. The evaluation refers to degradation as result of the combined action of the biotic and non-biotic factors, active in use class 3. Two common non-destructive methods were used to evaluate the wood exposed outdoors: visual assessment and microscopic evaluation. Rating of the exposed faces showed that untreated control samples presented the most severe biological degradation and cracking. Surface bioprotection minimised discolouration and was generally a beneficial treatment prior coating. The surface treatments investigated in this paper generally delayed the degradation phenomena but could not provide an efficient protection over a long exposure period

ARGUMENTS FOR REUSING OLD OAK WOOD RECOVERED FROM DEMOLITION

The main objective of this study was to find scientific arguments in favour of reusing recovered oak wood in order to reintegrate it in new types of structures. For this study six beams were selected, which had been recovered from a house built in 1831. Visual analysis revealed several defects and signs of degradation in the sapwood and inside the cracks. The recovered beams hadn’t been treated with any toxic chemicals. Bending strength, modulus of elasticity and compression strength parallel to the grain were investigated and microscopy and FTIR-ATR spectroscopy were used to check the quality of the apparently sound beam areas also used for the determination of mechanical properties. Macroscopic and microscopic analysis may not reveal any incipient fungal attack but FTIR analysis was proven to be effective. The obtained results open a new perspective for the future use of recovered old oak wood, due to the adequate mechanical properties and to the assumed means of eliminating degraded areas

TUNG OIL AND LINSEED OIL AS TRADITIONAL FINISHING MATERIALS IMPORTANT FOR FURNITURE CONSERVATION

Tung oil and linseed oil are two representative traditional drying oils wich were commonly employed, for centuries, for wood finishing. Therefore, their study in terms of properties, chemical structure features and alterations by ageing is important for furniture conservation. This paper focusses on some comparative properties of Tung oil and linseed oil as wood finishing materials. For this purpose, test wooden samples of Chinese walnut (Juglans mandshurica Maxim.) were coated with these materials by manual traditional techniques. Solids content of the oils was determined in order to approximate the thickness of the resulting film. The colour change brought about by coating of wood surfaces with these oils was measured in the CIELab system. Furthermore, an accelerated artificial ageing test under the action of temperature (100°C) was performed in order to evaluate and compare the ageing resistance of the two types of oils. Ageing phenomena were investigated by colour measurements and FTIR - ATR spectrometry. Both uncoated and oils coated wood surfaces suffered colour changes observed as darkening and colour shade shifting to red and yellow, but these were obviously more evident for the oil coated samples. The overal colour changes were maximum for the samples finished with linseed oil, while tung oil semmed to be more resistant. FTIR investigations for two types of oils highlighted similarities and differences in their chemical composition, curing and aspects of the thermally induced ageing mechanism. The later proved to be mainly an oxidative degradation process leading to formation of free fatty acids and other carbonyl containing compounds, as suggested by the broader carbonyl (1740 cm-1 ) and hydroxyl bands (3400 cm-1 )